If a cattle farmer were to group the different production cycles of his/her cattle herd into different asset group, it becomes clear that there are indeed different investment opportunities with different yield options.
One such asset group in each farmer’s portfolio is his replacement heifers. Unfortunately, it is also this important asset class that sometimes falls short in terms of performance, with negative long-term financial consequences.
Definition of a replacement heifer
A replacement heifer is a female animal that, under normal conditions, develops in such a way, that she reaches approximately 66% of her adult weight at around 18 months of age, after which she can be successfully bred and deliver a live calf at around 85% of her adult weight.
She must have a 90% chance of reconception and must wean at least 45% of her bodyweight. She is expected to wean a calf every year and maintain an intercalving period (ICP) of less than 400 days for the next ten to 12 years.
This definition of replacement heifers makes it clear that expectations are very high, and one can therefore understand why the yield (calf percentage, weaning weight and reconception percentage) is sometimes disappointing.
The role of good management
The influence of the fund manager in terms of the specific asset class cannot be overemphasised. This includes all aspects of herd management, from supervision and health management to nutrition management and selection. It still happens all too often that heifers are left somewhere in a mountain camp, almost forgotten, in an effort to make them ‘hardy’ – definitely a recipe for poor yield.
Similarly, when the replacement group is incorporated prematurely into the rest of the cow herd. The guideline is to manage replacement heifers as such until they are certified pregnant for a second time by a veterinarian. This basically entails a three-year programme. The heifer’s potential as a future herd cow is secured during this period.
Where does selection start?
Selection starts during the mothers’ breeding season. Give preference to heifers born early in the season. Not only do they wean at a heavier weight on average, but the daughters of early calving cows tend to calve at the same time during the season as their mothers. Ideally, 60% of cows should calve within the first three weeks of the calving season, and preference should be given to those heifers.
After weaning, selection measures such as weaning weight, correct conformation, good female traits and sexual development should be considered. This can be seen as the first round of selection and it is therefore recommended that producers make provision for the number of heifers selected, as some of the heifers may not make it through to the second round.
The second round of selection is during weaning, after the replacement heifers have calved. All heifers must be examined by the veterinarian pre-breeding to check for functional reproductive systems. Here aspects such as reconception percentage, weaning weight and growth rate are taken into account – these are all indicators of adaptability.
The veterinarian’s role
The veterinarian’s role and setting up a focused vaccination and deworming programme is a crucial one. Some of the most important vaccinations for heifers must be administered before weaning. Always regard timeous vaccination as a long-term investment in your heifers.
Pay particular attention to sexually transmitted diseases. This is especially important for producers who buy in replacement heifers. Insist on veterinary certification confirming that the animals have tested negative for existing sexual diseases.
Do not forget about annual booster vaccinations prior to the breeding season. This is the best way of building resistance against diseases.
Growth curve management
There are many studies on the growth rate of replacement heifers and the consequent reproduction performance in the herd. The earlier a heifer calves for the first time, the higher her productivity will be for the remainder of her life. It is, however, highly correlated with her level of nutrition, especially in the run-up to her first breeding season.
Experiments on three different breeds showed that the percentage of heat detection on 14-month-old heifers growing an average 700g per day, compared to heifers growing an average 350g per day, was almost 25% higher. Weigh your heifers regularly and follow a strategic supplement programme to reach the desired target weights.
Keep in mind that environmental and breed variations occur and that any nutritional programme needs to be adjusted accordingly. Also remember that heifers must reach their target weight before the start of the breeding season. The emphasis is on proactive management. – Phillip Lee, manager: Hinterland Animal Production